Heartworm disease, as the name suggests, are worms that infect the heart. In Australia, the prevalence of heartworm disease is highest in subtropical/tropical areas (Darwin up to 100%, Brisbane 34%) and northern temperate areas (Sydney 25%). Dogs are the most important hosts, but cats may also be susceptible.
Heartworm prevalence in Australia
Queensland and New South Wales are considered to be areas of higher risk whereas rates in South Australia are low (4,5).
Heartworm in dogs is prevalent across Australia and can be a serious and potentially fatal condition. Knowing how to prevent heartworm is essential for all dog owners. Luckily, there is plenty you can do to keep your pooch safe and healthy.
The leading states for heartworm incidence continue to be those around the lower Mississippi Delta, which has a climate where mosquitos thrive along with the presence of untreated dogs and wildlife that can carry infection.
Although heartworm in Australia was once considered mainly a problem of tropical and subtropical coastal regions, in recent decades it has become increasingly prevalent in Victoria. The condition can be extremely serious and often deadly.
In Melbourne, this is a low risk disease. If infected and not treated, it is usually fatal.
They then develop into adult worms over the course of six months. Fortunately, due to our climate and environment within the Melbourne area, mosquito numbers are low and therefore the incidence of heartworm in dogs is also low.
No state in the country is heartworm-free. According to the AHS survey, the top 5 states in heartworm incidence were Mississippi, Louisiana, Arkansas, Texas, and Tennessee—all states that have been in the top tier since the AHS began tracking incidence data in 2001.
Although there are fewer mosquitoes in the winter, there is still a risk that your pet could get heartworms if you stop giving heartworm prevention medication during this season. That's one reason veterinarians strongly recommend pets receive heartworm prevention medication year-round.
All dogs are at risk, even those that are indoors only. Untreated, heartworm disease can result in severe heart damage and even death.
Heartworm disease, as the name suggests, are worms that infect the heart. In Australia, the prevalence of heartworm disease is highest in subtropical/tropical areas (Darwin up to 100%, Brisbane 34%) and northern temperate areas (Sydney 25%). Dogs are the most important hosts, but cats may also be susceptible.
There are many heartworm preventatives that are available for both dogs and cats, like Comfortis Plus. Prevention should begin at six to eight weeks of age. Some forms come in a chewable tablet or as spot-on application. There are tablets or spot-on application for cats as well to prevent heartworm.
Signs of heartworm disease may include a mild persistent cough, reluctance to exercise, fatigue after moderate activity, decreased appetite, and weight loss. As heartworm disease progresses, pets may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen.
The American Heartworm Society has recommended year-round heartworm protection, without missing a dose. A missed heartworm pill leaves your pet exposed to becoming infected, which can happen even in winter. Making monthly heartworm medication part of your pet's health care regimen makes it easier to remember.
The monthly heartworm preventative we prescribe only lasts in a dog's or cat's body for one to two days, not 30 days, due to the lifestyle of the heartworm, it is only necessary for the pet to take the heartworm preventative every 30 days.
Year-round prevention is best! Talk to your dog's veterinarian to decide which preventive is best for your dog. The American Heartworm Society advocates to “Think 12." Give dogs 12 months of heartworm prevention and get them tested for heartworms every 12 months.
Heartworm prevention
Puppies can begin heartworm preventative medication from as young as 6/8 weeks old. If your pup is a little older (age 6 months plus) it is important that she is given a heartworm test before preventative medication is given.
The American Heartworm Society recommends that puppies and kittens be started on a heartworm preventive as early as the product label allows, and no later than 8 weeks of age.
Any dog of any age can, and should, be tested annually. Since it takes 6 months for a pet to develop a positive response on a heartworm test, we recommend that annual testing begin no earlier than 6 months after the end of the heartworm season of the previous year which is usually considered to be October 15th.
If your adult dog has been off heartworm preventative medication for longer than 6 months they will require testing before commencing any type of preventive treatment. Heartworm can be found all through the mainland of Australia. South Australia is not the most affected state but cases still appear.
Incidence of canine heartworm was estimated at 0.00% (95% confidence interval (CI): 0.00–0.0006) and prevalence at 0.002% (95%CI: 0.00–0.004) using conservative estimates of the South Australian dog population.
The human immune system is better equipped to recognize the worms in their immature state.
Dogs with heartworm disease, for example, require exercise restriction before and heartworm treatment, as well as for a short time after treatment. Physical activity increases the likelihood of adult worms causing a pulmonary thromboembolism, which may be fatal. Limiting a dog's physical activity decreases this risk.
The mature adult heartworms live in the heart and major blood vessels and cause heart failure. Puppies should start heartworm prevention at 12 weeks of age or earlier.
Proheart SR12 heartworm prevention yearly injection:
Up to 35kg – $186.75. Up to 50kg – $232.50. Heartworm test – $67.50.